A dark and black esophagus

A 70-year-old Italian man presented to our emergency department for dyspnea and confusion. He was affected by diabetes mellitus type 2, but he stopped his medication 10 days before. At admission, his vital signs were blood pressure of 60/50 mmHg, heart rate of 130 bpm, peripheral oxygen saturation of 94% in the Venturi Mask FiO₂ 40%, respiratory rate of 40/min, and body temperature of 36°C. Physical examination revealed hypoperfusion with a high Mottling Score and dark stools with a positive hydrogen peroxide reaction. He denied abdominal pain, nausea, and vomiting. Laboratory findings showed leucocytosis (White Blood Cells, WBC, 31,580/mm³; N 91.6%), Hemoglobin (Hb) 14.5 g/dL, Hematocrit Test (Hct) 49%, hyperglycaemia (>700 mg/L), and normal coagulation time. Arterial blood gas documented a metabolic acidosis with pH 6.95, Partial Pressure of Carbon Dioxide (pCO₂₎ 27.5 mmHg, HCO₃ 7.1 mmol/L, lactate 8.14 mmol/L (normal value <2), and elevated anion gap metabolic. He was first treated with IV therapy as follows omeprazole 80 mg, tranexamic acid 1 g, Ringer acetate 1000 cc, sodium bicarbonate 8.4% 100 mL, and magnesium sulfate 2 g. Then, a continuous IV infusion of Ringer 150 mL/h and omeprazole 8 mg/h was started. An Esophagogastroduodenoscopy (EGD) was arranged and showed circumferential blackening of the distal half of the esophagus.